JP7367123B2 - Needle - Google Patents

Description

The present invention relates to injection needles.

BACKGROUND ART In recent years, in the medical field, beauty field, etc., transdermal absorption of liquids such as drugs using liquid injection devices equipped with minute needle-like protrusions, also called microneedles, has attracted attention. According to this liquid injection device, it is possible to inject liquid into the body by inserting a microneedle into a relatively shallow layer of the skin such as the stratum corneum, and the pain felt by the subject is significantly greater than with a normal syringe. It is attracting attention as a minimally invasive means of administering liquids.

Patent Document 1 describes a needle-shaped and hollow first protrusion formed to protrude from the upper surface, which is one surface of a base sheet having a circular shape in plan view, and a first protrusion formed protruding from the vicinity of the first protrusion on the upper surface of the base material sheet. A fine protrusion tool is described which has a hollow second protrusion having a lower protrusion height than the first protrusion. In the same document, when the first protrusion is inserted into the skin from the distal end side, the first protrusion stops penetrating when the tip of the second protrusion in the vicinity comes into contact with the surface of the skin. It is described that the first protrusion is prevented from penetrating deeper into the skin. An opening is formed at the tip of the first protrusion, and the hollow part of the first protrusion communicates with the outside through the opening. The same document also describes that the tip of the first protrusion is inserted into the skin, and the liquid drug stored in the hollow part of the first protrusion is injected into the skin from the opening of the tip. Are listed.

Patent Document 2 describes a microneedle sheet in which a plurality of minute needles protruding from the surface are formed. This document describes that the needle includes a through needle in which a through hole penetrating from the front side to the back side is formed, and a dummy needle in which the through hole is not formed.

JP2017-38781A International Publication No. 2021/177317

In the microprotrusion device of Patent Document 1, the protrusion of the microprotrusion device is composed of a first protrusion portion that is hollow and has an opening, and a second protrusion portion that has a lower protrusion height than the first protrusion portion, and has a protrusion that does not touch the skin. Only the first protrusion is inserted, and the second protrusion, which has a lower protrusion height, functions as a stopper that limits the penetration depth of the first protrusion. Therefore, in the microprotrusion device of the same document, the effect of promoting blood flow caused by the protrusions being pressed against or inserted into the skin is limited, and there is room for improvement. In particular, only the first protrusion is disclosed as a protrusion that can stimulate the skin, and there is no disclosure of increasing the density of the protrusion or imparting a blood flow promoting effect uniformly over a wide range.
Patent Document 2 does not describe anything about controlling the puncture depth of the penetrating needle and the dummy needle.

The present invention relates to an injection needle that can control the depth of penetration into the skin, can inject liquid, and can effectively promote blood flow.

The present invention provides an injection needle having a protrusion projecting from the base of the sheet.
The injection needle of the present invention includes, as the protrusions, a hollow first protrusion that has an opening at its distal end, and a second protrusion that does not have an aperture at its distal end.
The first protrusion and the second protrusion are fine protrusions whose protrusion height from the surface of the base sheet is 5000 μm or less.
In the injection needle of the present invention, in the protrusion direction of the first protrusion, the tip position of the first protrusion is determined based on the criteria that the side closer to the surface of the sheet base is the lower side and the side farther from the surface of the sheet base is the higher side. and a puncture depth control section at an intermediate position that is lower than the surface of the sheet base and higher than the surface of the sheet base .
The injection needle of the present invention satisfies any one of the following (i) to (iii).
(i) The puncture depth control section is located at a position lower than the tip position of the second protrusion.
(ii) The protrusion protruding from the sheet base includes a third protrusion arranged around the first protrusion or the second protrusion, and the third protrusion has a distal end surface at the puncture depth. The puncture depth control unit is located at a lower position than the tip position of the second protrusion, or is located at the same height as the tip position of the second protrusion. There is.
(iii) a composite second protrusion in which the puncture depth control section is integrally formed around the second protrusion; the puncture depth control section is located at a position lower than the tip position of the second protrusion; or at the same height as the tip of the second protrusion.

According to the injection needle of the present invention, the depth of penetration into the skin can be controlled, liquid can be injected, and blood flow can be effectively promoted.

FIG. 1 is a cross-sectional view along the thickness direction of an injection needle according to a preferred embodiment of the present invention. FIG. 2 is a plan view of the injection needle shown in FIG. 1. FIG. 3 is a diagram schematically showing a state in which the injection needle shown in FIG. FIG. FIG. 4 is an explanatory diagram showing a method of measuring the tip diameter of a protrusion in an injection needle. FIGS. 5(a) to 5(e) are plan views schematically showing the arrangement pattern of protrusions on the injection needle shown in FIG. FIG. 6 is a sectional view showing another preferred embodiment of the present invention, and is a view corresponding to FIG. 1. FIG. 7 is a diagram schematically showing the usage state of the injection needle shown in FIG. 6, and is a diagram corresponding to FIG. 3. FIG. 8 is a plan view schematically showing an arrangement pattern of protrusions on the injection needle shown in FIG. 6. FIG. 9 is a sectional view showing still another preferred embodiment of the present invention, and is a view corresponding to FIG. 1. FIG. 10 is a diagram schematically showing the usage state of the injection needle shown in FIG. 9, and is a diagram corresponding to FIG. 3. FIG. 11 is a plan view schematically showing the arrangement pattern of protrusions on the injection needle shown in FIG. 9. FIG. FIG. 12(a) is a cross-sectional view schematically showing a modified example of the composite first protrusion and the composite second protrusion, and FIG. 12(b) is a cross-sectional view schematically showing a modified example of the second composite protrusion. . 13(a) is a cross-sectional view along the thickness direction of the injection needle of Comparative Example 1, and FIG. 13(b) is a plan view schematically showing the arrangement pattern of protrusions on the injection needle of Comparative Example 1. . FIG. 14(a) is a plan view schematically showing the arrangement pattern of protrusions on the injection needle of Example 5, and FIG. 14(b) is a plan view schematically showing the arrangement pattern of the protrusions on the injection needle of Example 6. FIG. 14C is a plan view schematically showing the arrangement pattern of protrusions in the injection needle of Example 7.

The present invention will be described below with reference to its preferred embodiments.
The injection needle 1A of the present invention has a projection projecting from the sheet base 20.
The injection needle 1A of the present invention typically has an overall flat sheet-like shape, and includes a sheet base 2 and a plurality of projections protruding from one surface of the sheet base 2. .
The injection needle 1A of the present invention typically has a protrusion arrangement region in which protrusions are arranged in a dispersed manner in a plane direction. The shape of the protrusion arrangement region can be any shape, such as a quadrilateral shape such as a square or a rectangle, a polygonal shape such as a circle, an ellipse, a pentagon, or a hexagon.

The protrusions of the injection needle 1A include a first protrusion 31 that has an opening 31a at its tip and is hollow, a second protrusion 32 that does not have an opening at its tip, and a first protrusion 31 and a second protrusion 32. It is preferable that the third protrusion 33 is lower in height than either of the protrusions. The first protrusion 31 is a minute protrusion having a hollow portion 31b, a so-called microneedle.
The second protrusion 32 and the third protrusion 33 may be hollow or solid. In the first embodiment, the second protrusion 32 and the third protrusion 33 are solid. Since the second protrusion 32 and the third protrusion 33 are solid, it is possible to reduce the amount of drug remaining in the injection needle 1A when injecting the drug from the injection needle 1A of the present invention.
Further, it is preferable that the third protrusion 33 has a flat end surface, that is, a straight line extending in the horizontal direction, or a curved line convex toward the protruding direction of the third protrusion.
The injection needle of the present invention preferably has the puncture depth control section 40 at an intermediate position that is lower than the tip position of the first protrusion 31 and higher than the surface of the sheet base 20. Typically, the tip end surface of the third protrusion 33 serves as the puncture depth control section 40 . An example of this is shown in FIG.
The puncture depth control section 40 controls the penetration depth of the first protrusion 31. It is preferable that the puncture depth control section 40 is located at a position lower than the tip position of the second protrusion 32.

In the injection needle 1A of the present invention, it is preferable that a plurality of second protrusions 32 are formed around one first protrusion 31. It is preferable that these second protrusions 32 have the same distance from the first protrusion 31 .
In the injection needle 1A of the present invention, it is preferable that a plurality of third protrusions 33 are formed around one first protrusion 31. It is preferable that these third protrusions 33 have the same distance from the first protrusion 31 .
More specifically, a pair of second protrusions 32, 32 are arranged so as to sandwich the first protrusion 31 in the first direction It is preferable that a pair of second protrusions 32, 32 are disposed so as to sandwich the second protrusions 32, 32 between them. Further, a pair of third protrusions 33, 33 are arranged so as to sandwich the first protrusion 31 in the first direction It is preferable that It is preferable that the third protrusion 33 is disposed between the first protrusion 31 and the second protrusion 32. An example of this is shown in FIG. Note that the position of the second protrusion 32 and the position of the third protrusion 33 may be reversed. That is, the second protrusion 32 may be arranged between the first protrusion 31 and the third protrusion 33.
In the injection needle 1A of the present invention, the unit arrangement pattern in which the first protrusion 31, the second protrusion 32, and the third protrusion 33 are arranged in a predetermined positional relationship is shared by the second protrusion 32 with an adjacent unit arrangement pattern. It is preferable that a plurality of them are continuous in the first direction X and the second direction Y in such a manner.
In the injection needle 1A of the present invention, typically the first protrusion 31 and the second protrusion 32 have a conical shape, and the third protrusion 33 has a cylindrical shape. More typically, the plurality of second protrusions 32 have the same shape and size, and the third protrusions 33 also have the same shape and size.

It is preferable that the injection needle 1A contains a thermoplastic resin. Specifically, it is preferable that the base material constituting the injection needle contains a thermoplastic resin. Typically, the injection needle 1A is preferably formed by plastically deforming a base sheet containing a thermoplastic resin by heating. The method of heating the base sheet may be a method of heating only a part of the base sheet, or a method of heating the entire base sheet. Methods of heating only a part of the base sheet to plastically deform the base sheet include a method of inserting a processing needle into the base sheet at the position where protrusions are to be formed while applying ultrasonic vibration, and a method of inserting a processing needle while applying ultrasonic vibration. Examples include a method of inserting a heated processing needle into the position where the protrusion is planned to be formed on the material sheet. As a method of heating the entire base sheet and plastically deforming the base sheet, for example, while heating the entire base sheet with a heating device such as a heater, the base sheet is heated at the position where protrusions are to be formed on the base sheet. , a method of inserting a processed needle, etc.
In order to make the second protrusion 32 and the third protrusion 33 solid, for example, the hollow part of the hollow second protrusion or the third protrusion formed by inserting a processing needle into the base material sheet is filled with solid material. It may be filled with the projection forming resin or other resin.

It is preferable that the injection needle 1A of the present invention has an opening 31a in the first protrusion 31. Thereby, the injection needle 1A of the present invention becomes a liquid injection device that can be used for percutaneous absorption of liquids such as drugs.
Typically, an opening 31a is formed at the tip of the first projection 31, and the hollow portion 31b of the first projection 31 communicates with the outside via the opening 31a. The opening 31a is a through hole that penetrates the sheet base 2 forming the first protrusion 31 in the thickness direction, and is preferably located at the tip of the conical first protrusion 31. The hollow portion 31b of the first protrusion 31 functions as a reservoir or passageway for liquid discharged to the outside from the opening 31a. Here, the tip of the first protrusion 31 means a region closer to the tip than the intermediate position of the protrusion height H1 from the surface of the seat base 2 to the tip of the first protrusion 31.
When the injection needle 1A is used for transdermal absorption of a drug, the tip of the first protrusion 31 is inserted into the skin S, and the liquid drug L stored in the hollow part 31b of the first protrusion 31 is It is injected into the skin S through the opening 31a at the tip. The hollow portion 31b of the first protrusion 31 functions as a drug storage portion in this way, typically when no drug is supplied from the outside.
When a drug is supplied from the outside, for example, when a drug supply device (not shown) such as an applicator is used together with the injection needle 1A, the hollow portion 31b functions as a passage for the drug. The drug supply device is configured by arranging a sheet-like member on the back side of the injection needle 1A, forming a drug storage space between the back surface of the injection needle 1A and the sheet-like member, and pressing the sheet-like member. The medicine may be supplied to the first protrusion 31 (see Japanese Patent Laid-Open No. 2020-096790 [0011]).

It is preferable that the injection needle 1A has a second protrusion 32 in addition to the first protrusion 31.
When the height H2 of the second protrusion 32 is higher than the height H3 of the puncture depth control section 40, when the injection needle 1A is pressed against the skin and the first protrusion 31 is inserted into the skin from the tip side. At the same time, the second protrusion 32 is also inserted into the skin. When the second protrusion 32 is inserted into the skin, the second protrusion 32 stimulates the skin and exerts an effect of promoting blood flow. Therefore, according to the injection needle 1A having this configuration, the first protrusion 31 can inject liquid into the skin, and the second protrusion 32 can promote blood flow. Unlike the case where the fine protrusion device of Patent Document 1 has only a first protrusion that can inject liquid into the skin, the injection needle 1A has a first protrusion 31 and a second protrusion. Both protrusions 32 can stimulate a wide range of skin. Therefore, in the fine protrusion device of Patent Document 1, unlike the case where only the first protrusion is increased for the purpose of stimulating the skin widely, when applying the injection needle 1A to the skin, the protrusion that does not partially penetrate the skin is Even if there is, it is not necessarily the first protrusion that has an opening, so the probability of liquid leakage can be suppressed.

When the injection needle 1A is pressed against the skin, the second protrusion 32 may only be pressed against the skin without being penetrated into the skin. Typically, the height H2 of the second protrusion 32 and the distance H3 from the surface of the sheet base 2 to the puncture depth control section 40 are equal. In this case as well, the second protrusion 32 can stimulate the skin and exert an effect of promoting blood flow.
Moreover, it is preferable that the injection needle 1A has a puncture depth control section 40 in addition to the first protrusion 31 and the second protrusion 32. As described above, in the injection needle 1A, it is preferable that the distal end surface of the third protrusion 33 is the puncture depth control part 40, and the first protrusion 31 and the second protrusion 32 are inserted into the skin from the distal end side. When the puncture depth control section 40 comes into contact with the surface of the skin, the first protrusion 31 and the second protrusion 32 stop being inserted, and the first protrusion 31 and the second protrusion 32 reach a deeper part of the skin. 32 is prevented from penetrating. That is, the puncture depth control section 40 functions as a stopper that limits the penetration depth of the first protrusion 31 and the second protrusion 32.
An example having these configurations is shown in FIG.
The presence or absence of a blood flow promoting effect can be determined using various known methods, such as determining whether a flare reaction occurs on the skin or visualizing the blood flow distribution using a laser blood flow meter (LSFG). can be judged.

In this way, the injection needle 1A allows the penetration depth of the first protrusion 31 and the second protrusion 32 into the skin to be controlled, so that the drug can be transdermally absorbed to any desired depth of the skin. At the same time, blood flow can be effectively promoted. Therefore, according to the injection needle 1A, it is possible to maximize the effect of the drug by adjusting the insertion depth of the first protrusion 31 depending on the type of drug and the like. Further, by adjusting the insertion depth of the second protrusion 32 according to the desired degree of blood flow promotion effect, it is possible to effectively produce the blood flow promotion effect.
Furthermore, the first protrusion 31 and the second protrusion 32 are inserted into the stratum corneum S11, which is the superficial layer of the skin S, or the layer S12, which is located inside the stratum corneum. By preventing the first protrusion 31 and the second protrusion 32 from penetrating the subcutaneous tissue U, the pain associated with percutaneous absorption can be significantly reduced compared to conventional syringes. Generally, the skin S includes an epidermis S1 including the stratum corneum S11 that constitutes the surface layer of the skin S, a dermis S2 located inside the epidermis S1, and a subcutaneous tissue (not shown) located inside the dermis S2. including. The layer S12 located inside the stratum corneum S11 in the epidermis S1 typically includes the stratum granulosum, stratum spinosum, and stratum basale in the order of proximity to the stratum corneum S11, and the dermis S2 is located inside the basal layer. is located.

When transdermal absorption of a drug is performed using a syringe equipped with a needle that does not have the puncture depth control unit 40, the needle passes through the stratum corneum and penetrates into the dermis S12 or the dermis S2, which is located inside the stratum corneum. Since the injection needle penetrates deep into the subcutaneous tissue, the person who received the injection needle had to endure the pain caused by the insertion of the injection needle. However, according to the injection needle 1A, the drug can be absorbed through the skin and blood flow can be promoted while reducing the pain felt by the person who has inserted the injection needle.
From the viewpoint of minimally invasive transdermal absorption and pain control, the puncture depth control unit 40 controls the tips of the first protrusion 31 and the second protrusion 32 so that they do not reach the dermis and subcutaneous tissue U. It is preferable that there be some, and more preferably that it can be controlled so that it does not even reach the region S12 located inside the stratum corneum. The penetration depth of the first protrusion 31 and the second protrusion 32 corresponds to the distance in the height direction Z between the tip of the first protrusion 31 and the second protrusion 32, respectively, and the puncture depth control section in the vicinity thereof. By appropriately adjusting this distance in the height direction Z, the above effect can be achieved more reliably. In the present invention, "minimally invasive" means that when an injection needle is pressed against the skin, the stratum corneum and areas located inside the stratum corneum are injured, but the dermis and subcutaneous tissue are not injured.

In the injection needle 1A of the present invention, the blood flow promoting effect is provided by the second protrusion 32, and the blood flow promoting effect and liquid injection is provided by the first protrusion 31, and the roles of the first protrusion 31 and the second protrusion 32 are different. It's set. Thereby, the amount of liquid to be injected can be efficiently suppressed compared to the case where a large number of protrusions into which liquid can be injected are provided for the purpose of obtaining a blood flow promoting effect. In particular, when liquid is delivered from one drug reservoir to multiple injectable protrusions, the degree of penetration into the skin tends to vary depending on each protrusion, but according to the injection needle 1A of the present invention, The drug can be injected uniformly, preventing leakage, and making it possible to inject to a uniform depth under the skin. Further, the range into which the liquid is injected can be suppressed to the minimum effective range. The second protrusion 32 serves as a guide/indicator for vertically inserting the injection needle 1A into the skin, and the second protrusion 32 restrains deformation of the skin, thereby making it easier to insert the first protrusion 31. There is also. In addition, for example, by arranging the second protrusion particularly on the outer periphery of the injection needle 1A, when using the injection needle, the injection needle 1A is not unavoidably perpendicular to the skin, but is inclined to the skin. If the injection needle 1A is inserted into the skin, the projections placed on the outer circumference of the injection needle 1A may not be able to penetrate the skin enough depending on the direction, but the protrusions placed on the inner circumference of the injection needle 1A may One protrusion easily penetrates into the skin sufficiently, and the drug can be injected without leaking into the skin S. That is, the injection needle 1A of the present invention can easily control the amount of liquid to be injected and the range in which the liquid is injected, and can efficiently inject the drug.

From the viewpoint of significantly reducing the pain associated with transdermal absorption or reliably injecting the drug into the skin S from the first protrusion 31, the height of the tip position of the first protrusion 31 and the position of the puncture depth control unit 40 is determined. The difference is preferably 1 μm or more, more preferably 5 μm or more. The height difference is, in other words, the difference H1-H3 between the protrusion height H1 of the first protrusion 31 and the distance H3 from the surface of the sheet base 2 to the puncture depth control section 40.
Further, the difference H1-H3 is preferably 5000 μm or less, more preferably 4000 μm or less, from the viewpoint of not damaging the dermis more than necessary.
Further, the difference H1-H3 is preferably 1 μm or more and 5000 μm or less, more preferably 5 μm or more and 4000 μm or less.
A point of view that can significantly reduce pain associated with the blood flow promoting effect of the second protrusion 32, suppress poor puncture of the second protrusion due to the elasticity of the skin, and sufficiently penetrate the second protrusion into the skin. Therefore, the protrusion height H2 of the second protrusion 32 is preferably at least the distance H3 from the surface of the sheet base 2 to the puncture depth control unit 40, that is, H2≧H3, and more preferably H2>H3. .
From the same viewpoint, the difference H2-H3 is preferably 0 or more, more preferably 100 μm or more, and still more preferably 400 μm or more.
Further, the difference H2-H3 is preferably 5000 μm or less, more preferably 4000 μm or less, from the viewpoint of not damaging the skin more than necessary.
Further, the difference H2-H3 is preferably 0 or more and 5000 μm or less, more preferably 100 μm or more and 5000 μm or less, and still more preferably 400 μm or more and 4000 μm or less.

The first protrusion 31 is designed to provide a blood flow promoting effect more reliably, to ensure that the first protrusion 31 is punctured, and to suppress leakage of medicine caused by insufficient puncture. It is preferable that the height is higher than that of the two protrusions 32. More specifically, the difference H1-H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is preferably 1 μm or more, more preferably 5 μm or more.
Further, the difference H1-H2 is preferably 5000 μm or less, more preferably 4000 μm or less, from the viewpoint of making it easier to achieve both ease of liquid injection and blood flow promoting effect.
Further, the difference H1-H2 is preferably 1 μm or more and 5000 μm or less, more preferably 5 μm or more and 4000 μm or less.

The protrusion height H1 of the first protrusion 31 suppresses penetration from being inhibited by deformation of the skin when the first protrusion 31 is pressed against the skin, improves puncture performance, and allows the drug to be delivered into the skin S. From the viewpoint of reliable injection, the thickness is preferably 10 μm or more, more preferably 20 μm or more.
Further, from the viewpoint of minimal invasion, the protrusion height H1 of the first protrusion 31 is preferably 5000 μm or less, more preferably 4000 μm or less.
Further, the protrusion height H1 of the first protrusion 31 is preferably 10 μm or more and 5000 μm or less, more preferably 20 μm or more and 4000 μm or less, from the viewpoint of achieving both improved puncture performance and minimal invasiveness.

The protrusion height H2 of the second protrusion 32 is preferably 10 μm or more, more preferably 20 μm or more, from the viewpoint of stimulating the skin and promoting blood flow by pressing it against the skin.
Further, from the viewpoint of minimal invasion, the protrusion height H2 of the second projection 32 is preferably 5000 μm or less, more preferably 4000 μm or less.
Further, from the viewpoint of improving blood flow promotion, the protrusion height H2 of the second protrusion 32 is preferably 10 μm or more and 5000 μm or less, and more preferably 20 μm or more and 4000 μm or less.
The distance H3 from the surface of the sheet base 2 to the puncture depth control section 40 is preferably 5 μm or more, more preferably 10 μm or more.
Further, from the viewpoint of improving the puncturing property of the first protrusion 31, the distance H3 is preferably 4000 μm or less, more preferably 3000 μm or less.
Further, the distance H3 is preferably 5 μm or more and 4000 μm or less, more preferably 10 μm or more and 3000 μm or less.

In reality, the diameter of the tip of the first protrusion 31 is preferably 1 μm or more, more preferably 5 μm or more.
Further, the diameter of the tip of the first protrusion 31 is preferably 300 μm or less, more preferably 100 μm or less, from the viewpoint of preventing penetration from being inhibited by the elasticity of the skin.
The diameter of the tip of the first protrusion 31 is preferably 1 μm or more and 300 μm or less, more preferably 5 μm or more and 100 μm or less.
The diameter of the tip of the second protrusion 32 is preferably 1 μm or more, more preferably 5 μm or more.
Further, the diameter of the tip of the second protrusion 32 is preferably 300 μm or less, more preferably 200 μm or less, from the viewpoint of improving the blood flow promoting effect.
Further, the diameter of the tip of the second protrusion 32 is preferably 1 μm or more and 300 μm or less, more preferably 5 μm or more and 200 μm or less.

The diameter of the tip of the third projection 33 is preferably 2 μm or more, more preferably 10 μm or more, from the viewpoint of functioning as a stopper to prevent the first projection 31 from being inserted more than necessary.
The tip diameter of the second protrusion 32 may be greater than or equal to the tip diameter of the first protrusion 31 , or may be less than or equal to the tip diameter of the first protrusion 31 .
Further, the diameter of the tip of the third protrusion 33 is preferably 2000 μm or less, more preferably 100 μm or less, from the viewpoint of improving the density of the first protrusion, the second protrusion, etc.
Further, the diameter of the tip of the third protrusion 33 is preferably 2 μm or more and 2000 μm or less, more preferably 10 μm or more and 100 μm or less.
The tip diameter of the third protrusion 33 may be greater than or equal to the tip diameter of the first protrusion 31 , or may be less than or equal to the tip diameter of the first protrusion 31 .
The tip diameters of the first to third protrusions 31 to 33 are measured by the following method.

[Method for measuring the tip diameter of the protrusion on a syringe needle]
The tip of the protrusion to be measured (first protrusion 31, second protrusion 32, or third protrusion 33) is observed as shown in FIG. 4 using a scanning electron microscope (SEM) or a microscope. Next, as shown in FIG. 4, an imaginary straight line ILa is extended along a straight line portion on one side 1a of both sides 1a and 1b, and an imaginary straight line ILb is extended along a straight line portion on the other side 1b. Then, on the tip side, a point where one side 1a departs from the virtual straight line ILa is determined as a first tip point 1a1, and a point where the other side 1b departs from the virtual straight line ILb is determined as a second tip point 1b1. The length L of the straight line connecting the first tip point 1a1 and the second tip point 1b1 obtained in this way is measured. The length of the measured straight line is defined as the tip diameter of the protrusion to be measured.

As described above, the first protrusion 31 preferably has an opening 31a at its tip. Preferably, the opening 31a is not formed at the tip of the first protrusion 31, but is formed on the side surface of the first protrusion 31. If the aperture 31a is formed in such a position, the aperture 31a will not be easily crushed when the first protrusion 31 is punctured into the skin, and liquid such as a medicine can be injected from the injection needle 1A into the skin through the aperture 31a. Can be stably supplied.

The first protrusion 31 can be arranged at any position within the protrusion arrangement area, but is located inside the protrusion arrangement area than the second protrusion 32, that is, closer to the centroid side of the protrusion arrangement area. It is preferable. By doing so, when the injection needle 1A is pressed against the skin, a load is easily applied to the first protrusion 31, and the first protrusion 31 becomes easier to puncture the skin. Further, it is also preferable that the first protrusion 31 is surrounded by the second protrusion 32. By doing this, the site where the first protrusion 31 is punctured is surrounded by an area where blood flow is promoted and immunity is induced by the weak stimulation of the second protrusion 32, and the drug injected by the first protrusion 31 is It is thought that the medicinal efficacy can be improved. Furthermore, when using the injection needle 1A, the injection needle 1A may inevitably not be perpendicular to the skin and may be inserted at an angle to the skin, and in this case, the first protrusion 31 By being located on the centroid side, the first protrusion 31 can be stably inserted into the skin no matter which direction the injection needle 1A is tilted with respect to the skin, and the injection needle 31 can be stably inserted into the skin. It is possible to effectively prevent the medicine from leaking even when the medicine is used sufficiently. From the viewpoint of making these effects more noticeable, it is preferable that the second protrusion 32 be located at the outermost side of the protrusion arrangement area.

The arrangement pattern of the first protrusion 31, the second protrusion 32, and the third protrusion 33 is not particularly limited.
From the viewpoint of accurately controlling the puncture depth, an arrangement in which one or both of the first protrusion 31 and the second protrusion 32 are arranged between a pair of adjacent third protrusions 33 (hereinafter referred to as "first arrangement") is adopted. ) is preferable. Either or both of the first protrusion 31 and the second protrusion 32 that do not have a puncture depth control part are disposed between the composite protrusions (first composite protrusion 51 or second composite protrusion 52) that have a puncture depth control part. It is also preferable to have a second sequence (hereinafter referred to as "second sequence").
The protrusions located between the third protrusions 33 in the first arrangement, or the protrusions located between the compound protrusions in the second arrangement are only the first protrusion 31, only the second protrusion 32, or the first protrusion 31 and the second protrusion 32. The number of protrusions located between the third protrusions 33 or between the composite protrusions is preferably 1 or more and 4 or less, and more preferably 1 or 2.

For example, the arrangement patterns shown in FIGS. 5(a), (b), and (e) include, as the first arrangement, a first arrangement arranged in the first direction X, a first arrangement arranged in the second direction Y, and a first arrangement arranged in the second direction Y. It includes a first array arranged in a direction inclined with respect to both the first direction X and the second direction Y, more specifically, in a direction inclined at an angle of 45 degrees. The arrangement patterns shown in FIGS. 5(d) and (c) include a first arrangement in which a plurality of protrusions, which are the first or second protrusions 31 and 32, are arranged between the third protrusions 33. I'm here. The arrangement patterns shown in FIGS. 8A and 11A include a second arrangement arranged in the first direction X and a second arrangement arranged in the second direction Y as the second arrangement. The arrangement patterns shown in FIGS. 8(c) and 11(b) include, as the second arrangement, a second arrangement arranged in the first direction X, a second arrangement arranged in the second direction Y, and a second arrangement arranged in the first direction It includes a second arrangement arranged in a direction inclined with respect to both directions of the second direction Y, more specifically, in a direction inclined at an angle of 45 degrees.
It is preferable that a plurality of first arrays or second arrays exist in the protrusion arrangement region, and it is preferable that a plurality of the first array or the second arrangement exist in a state of being dispersed in the plane direction of the protrusion arrangement region.

From the viewpoint of accurately controlling the puncture depth, at least three or more third protrusions 33 are arranged so as to surround the first protrusion 31 or the second protrusion 32 (hereinafter referred to as "third arrangement"). ), or may have an arrangement in which at least three or more protrusions, which are the second protrusions 32 or the third protrusions 33, are arranged so as to surround the first protrusion 31 (hereinafter referred to as "fourth arrangement"). preferable. At least three or more composite protrusions (first composite protrusion 51 or second composite protrusion 52) having a puncture depth control section surround the first protrusion 31 or second protrusion 32 that does not have a puncture depth control section. It is also preferable to have an array arranged like this (hereinafter referred to as "fifth array").
The protrusions surrounded by the third protrusions 33 in the third arrangement, or the protrusions surrounded by the composite protrusions in the fifth arrangement are only the first protrusions 31, only the second protrusions 32, or the first protrusions 31 and the second protrusions 32. It can be both. Regarding the third arrangement or the fifth arrangement, the number of protrusions surrounded by the third protrusion 33 or the composite protrusion is preferably one or more and four or less, and more preferably one or two. Regarding the fourth arrangement, the number of first protrusions 31 surrounded by the second or third protrusions 32, 33 is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less.
For example, the arrangement patterns shown in FIGS. 5(a), (b), and (e) include a third arrangement in which one protrusion, which is the first or second protrusion 31, 32, is surrounded by the third protrusion 33. Contains. The arrangement pattern shown in FIGS. 5(c) and 5(d) includes a third arrangement in which a plurality of protrusions, which are the first or second protrusions 31 and 32, are surrounded by the third protrusion 33.
It is preferable that a plurality of third arrays, fourth arrays, or fifth arrays exist in the protrusion arrangement region, and preferably that a plurality of them exist in a state of being dispersed in the plane direction of the protrusion arrangement region.

The arrangement pattern of the first protrusion 31, the second protrusion 32, and the third protrusion 33 is, for example, as shown in FIG. The second protrusions 32, 32 may be arranged, and the third protrusion 33 may be arranged so as to sandwich each second protrusion 32 in the first direction X or the second direction Y. Further, as shown in FIG. 5(b), a second protrusion 32 and a third protrusion 33 are arranged to surround the first protrusion 31, and the second protrusion 32 is larger than the third protrusion 33. It may be placed outside. Further, as shown in FIG. 5(c), a second protrusion 32 and a third protrusion 33 are arranged to surround the first protrusion 31, and the second protrusion 32 is larger than the third protrusion 33. It may be placed inside. Further, as shown in FIG. 5(d), the first protrusion 31 and the third protrusion 33 are arranged so as to surround the second protrusion 32, and the third protrusion 33 is larger than the first protrusion 31. It may be placed outside. Further, as shown in FIG. 5E, a first protrusion 31 and a third protrusion 33 are arranged to surround the second protrusion 32, and the third protrusion 33 is larger than the first protrusion 31. It may be placed inside. In addition, in FIGS. 5(a) to 5(e), the first protrusion 31 is indicated by upward hatching to the right, the second protrusion 32 is indicated by downward hatching to the right, and the third protrusion 33 is indicated by dotted hatching. .

In a plan view of the sheet base 2, the distance D between the tips of adjacent protrusions prevents deformation of the skin from interfering when adjacent protrusions are pressed against the skin, making it difficult for the first protrusion to be inserted. From the viewpoint of this, it is preferably 0.01 mm or more, more preferably 0.02 mm or more, even more preferably 0.1 mm or more, and particularly preferably more than 0.5 mm.
Further, the distance D is preferably 10 mm or less, more preferably 5 mm or less, and still more preferably 3 mm or less, from the viewpoint of ensuring that the blood flow improving effect induced by adjacent protrusions can be obtained in the applicable range without any gaps. .
Further, the distance D is preferably 0.01 mm or more and 10 mm or less, more preferably 0.1 mm or more and 5 mm or less, and even more preferably more than 0.5 mm and 3 mm or less.
Adjacent protrusions are the two protrusions with the shortest distance between their vertices, and if one protrusion is surrounded by multiple other protrusions with the same distance between them, It is a protrusion. The distance D is measured by considering only the first protrusion 31 and the second protrusion 32 as adjacent protrusions. That is, even if there is a third protrusion 33 whose distal end surface is the puncture depth control section 40, the distance D is measured while ignoring the third protrusion 33.

The thickness T of the sheet base 2 of the injection needle 1A is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more.
Further, from the viewpoint of making it easier to press the injection needle 1A against the skin, the thickness T is preferably 2000 μm or less, more preferably 1000 μm or less, and still more preferably 500 μm or less.
Further, the thickness T is preferably 5 μm or more and 2000 μm or less, more preferably 10 μm or more and 1000 μm or less, and still more preferably 20 μm or more and 500 μm or less (see FIG. 1).

The thickness T of the sheet base 2 can be measured by the following method.
<How to measure the thickness of the base of the sheet>
The sheet base 2 of the injection needle 1A is observed using a SEM or a microscope under a predetermined magnification as shown in FIG. Next, as shown in FIG. 1, the distance along the thickness direction Z of the sheet base 2 from the surface of the sheet base 2 from which the protrusions protrude to the surface opposite to this surface is measured. The distance thus measured is defined as the thickness T of the base.

The injection needle 1A may have only one first protrusion 31, but preferably has a plurality of first protrusions 31.
Furthermore, it is preferable that the injection needle 1A has a region in which the number N1 of first protrusions 31 or the number N2 of second protrusions per 1 cm ² is as follows when viewed from above.
The number N1 of the first protrusions 31 or the number N2 of the second protrusions is preferably 1 or more, more preferably 5 or more, still more preferably 10 or more, from the viewpoint of efficiently injecting the liquid. be.
Further, the number N1 of the first protrusions 31 or the number N2 of the second protrusions is preferably 400 or less, from the viewpoint of easily controlling the amount of liquid to be injected and the range in which the liquid is injected. The number is more preferably 300 or less, and even more preferably 200 or less.
In addition, from the viewpoint of achieving both of these, the number N1 of the first protrusions 31 or the number N2 of the second protrusions is preferably 1 or more and 400 or less, more preferably 5 or more and 300 or less, and still more preferably 10 or more. The number is 200 or less.

The injection needle 1A may have only one second protrusion or a plurality of second protrusions, but preferably has a plurality of first protrusions 31.
The injection needle 1A preferably has an area where the total number N1+N2 of the first protrusions 31 and second protrusions 32 per 1 cm ² is as follows when viewed from above.
The total number N1+N2 is preferably 2 or more, from the viewpoint of causing a flare reaction in the entire area to which the injection needle 1A is applied, making it easier to realize the blood flow promotion effect, and from the viewpoint of making it possible to inject the liquid efficiently. , more preferably 5 or more, still more preferably 10 or more, particularly preferably 20 or more, particularly preferably 30 or more.
The total number N1+N2 is preferably 500 or less, more preferably 300 or less, and still more preferably 200 from the viewpoint of easily controlling the amount of liquid to be injected and the range in which the liquid is injected. or less, particularly preferably less than 200 pieces.
From the viewpoint of achieving both of these, the total number N1+N2 is preferably 10 to 500, more preferably 20 to 300, and even more preferably 30 to less than 200.

The ratio N2/N1 of the number N2 of the second protrusions to the number N1 of the first protrusions 31 per 1 ^cm2 efficiently causes a flare reaction around the first protrusions 31 into which the liquid is injected, resulting in a blood flow promoting effect. In addition, when the injection needle 1A is pressed against the skin, the probability of liquid injection can be improved by preventing the first protrusion 31 from being punctured into the skin and ensuring that the first protrusion 31 is punctured. From this point of view, it is preferably 0.01 or more, more preferably 0.1 or more, even more preferably 0.5 or more, particularly preferably 1 or more, particularly preferably 2.4 or more.
The ratio N2/N1 is preferably 100 or less, from the viewpoint of enabling puncturing with a small puncturing pressure, reducing the amount of liquid injected per each first protrusion, and injecting the liquid efficiently. , more preferably 50 or less, still more preferably 10 or less.
From the viewpoint of achieving both of these, the ratio N2/N1 is preferably 0.01 or more and 100 or less, more preferably 1 or more and 50 or less, and still more preferably 2.4 or more and 10 or less.

The number of first protrusions 31 per 1 cm ² when the injection needle 1A is viewed from above can be measured by the following method.
<Method of measuring the number of first protrusions per 1 ^cm2 >
The number of first protrusions 31 per 1 cm ² is the number (pieces) of first protrusions 31 included in a protrusion arrangement area in which a plurality of fine protrusions 3 are arranged in a dispersed manner in a plane direction. It can be calculated by dividing by the total area (cm ² ). The total area of the protrusion arrangement area is defined as the area of the area surrounded by the imaginary line connecting the vertices of each protrusion arranged at the outer edge of the area when the injection needle 1A is viewed from above. If the number of protrusions on the injection needle 1A is two or less, it can be measured by counting the number of first protrusions 31 included in a 1 cm square area when the injection needle 1A is viewed from above.

By using the injection needle of the present invention, a blood flow promoting effect can be obtained in a wide range where the first protrusion and the second protrusion are arranged, and the drug can be reliably injected into the skin.
When a drug is injected into the skin, blood flow around the area where the drug is injected improves, making it easier for the drug to be absorbed into the skin, preventing unabsorbed drugs from flowing out of the skin, and increasing the effectiveness of the drug. The present inventors believe that this will be easier to obtain.

Next, another embodiment of the injection needle of the present invention will be described. Regarding these embodiments, only the points that are different from the previously described embodiments will be explained. For points that are not particularly explained, the explanations for the previously described embodiments will be applied as appropriate, and the same members will be given the same reference numerals. It has been done. Examples of these are shown in FIGS. 6-8 and 9-11.

The injection needle of the present invention preferably includes a composite first protrusion 51 in which the third protrusion and the puncture depth control section 40 are integrally formed in the direction of the seat base of the first protrusion 31. An example of an injection needle (hereinafter also referred to as "injection needle 1B") including the composite first protrusion 51 will be described. In the injection needle 1B, the first protrusion 31 has a puncture depth control section 40 integrally formed on the outer circumference of the base side portion. More specifically, an enlarged diameter portion 41 is formed at the base side portion, and a stepped portion projecting outward in the radial direction of the first protrusion 31 is formed at the upper end of the enlarged diameter portion 41 . The stepped portion serves as a puncture depth control section 40.
The overhang length L1 of the stepped portion of the composite first protrusion 51 is preferably 0.002 mm or more, more preferably 0.01 mm or more, from the viewpoint of functioning as a stopper to prevent the first protrusion 31 from being inserted more than necessary. .

In addition, the length L1 is preferably 2 mm or less, more preferably 0 mm or less, from the viewpoint of improving the density of the first protrusion 31 and the second protrusion 32 and obtaining a blood flow promoting effect in a wide range where the fine protrusion device is applied. .1 mm or less.
Further, the length L1 is preferably 0.002 mm or more and 2 mm or less, more preferably 0.01 mm or more and 0.1 mm or less.
The length L1 is a straight line distance measured along a plane orthogonal to the height direction between the inner end and the outer end of the step, and as shown in FIG. This is the distance between two contact points between each of the outer ends and tangents P1 and P2 that form 45° with respect to the center line CL of the first protrusion.

Also in the injection needle 1B, when the composite first protrusion 51 and the second composite protrusion 32 are inserted into the skin from the distal end side, the puncture depth control section 40 comes into contact with the surface of the skin, thereby causing the composite first protrusion 51 and the second protrusion 32 to The insertion of the protrusion 51 and the second protrusion 32 is stopped, and the composite first protrusion 51 and the second protrusion 32 are prevented from penetrating deeper into the skin. In the composite first protrusion 51, the puncture depth control section 40 is integrally formed around the first protrusion 31, so that it is easier to insert the composite first protrusion 51 into a deeper part of the skin. This can be reliably prevented. An example of this is shown in FIG.

The arrangement pattern of the composite first protrusion 51 and the second protrusion 32 is not particularly limited. For example, as shown in FIG. 8(a), a pair of second protrusions 32, 32 may be arranged to sandwich the composite first protrusion 51 in the first direction X and the second direction Y. Further, as shown in FIG. 8(b), the second protrusion 32 may be arranged to surround the first composite protrusion 51. Further, as shown in FIG. 8(c), a composite first protrusion 51 may be arranged to surround the second protrusion 32. In addition, in FIGS. 8A and 8B, the composite first protrusion 51 is shown by upward hatching to the right, and the second protrusion 32 is shown by hatching downward to the right.

The injection needle of the present invention preferably includes a composite second protrusion 52 in which a puncture depth control section 40 is integrally formed around the second protrusion 32. An example of an injection needle (hereinafter also referred to as "injection needle 1C") including the composite second protrusion 52 will be described. In the injection needle 1C, the second protrusion 32 has a puncture depth control section 40 integrally formed on the outer periphery of the base side portion. More specifically, an enlarged diameter portion 41 is formed at the base side portion, and a stepped portion projecting outward in the radial direction of the second protrusion 32 is formed at the upper end of the enlarged diameter portion 41 . The stepped portion serves as a puncture depth control section 40. An example of this is shown in FIG.
The overhang length L2 of the stepped portion of the composite second protrusion 52 is preferably 0.002 mm or more, more preferably 0.01 mm or more, from the viewpoint of functioning as a stopper to prevent the second protrusion 32 from being inserted more than necessary. .
Further, the length L2 is preferably 2 mm or less, more preferably 0.2 mm or less, from the viewpoint of improving the density of the first protrusion 31 and the second protrusion 32 and obtaining a blood flow promoting effect in a wide range where the injection needle is applied. It is 1 mm or less.
Further, the length L2 is preferably 0.002 mm or more and 2 mm or less, more preferably 0.01 mm or more and 0.1 mm or less.
The length L2 can be measured by the same means as the length L1.

Also in the injection needle 1C, when the first protrusion 31 and the composite second protrusion 52 are inserted into the skin from the distal end side, the puncture depth control section 40 comes into contact with the surface of the skin, so that the first protrusion 31 and the composite second protrusion 52 are stopped, and the first protrusion 31 and the composite second protrusion 52 are prevented from penetrating deeper into the skin. In the second composite protrusion 52, the puncture depth control section 40 is integrally formed around the second protrusion 32, making it easier for the second composite protrusion 52 to be inserted into a deeper part of the skin. This can be reliably prevented. An example of this is shown in FIG.

The arrangement pattern of the first protrusion 31 and the composite second protrusion 52 is not particularly limited. For example, as shown in FIG. 11(a), a pair of composite second protrusions 52, 52 may be arranged to sandwich the first protrusion 31 in the first direction X and the second direction Y. Further, as shown in FIG. 11(b), a composite second protrusion 52 may be arranged to surround the first protrusion 31. Further, as shown in FIG. 11(c), the first protrusion 31 may be arranged to surround the composite second protrusion 52. In addition, in FIGS. 9A and 9B, the first protrusion 31 is indicated by upward hatching to the right, and the composite second protrusion 52 is indicated by downward hatching to the right.

Next, matters common to each of the embodiments described above will be explained.
The injection needles 1A, 1B, and 1C of each of the embodiments described above ensure ease of handling of the material, strength and workability of the injection needle, hardness of the first protrusion 31 and the second protrusion 32, and facilitate injecting liquid. At the same time, it is preferable to contain a thermoplastic resin from the viewpoint of obtaining and improving the blood flow promoting effect. More preferably, the injection needle is formed from a base sheet containing a thermoplastic resin.
It is preferable that the base sheet contains thermoplastic resin as a main constituent material. The main constituent material means that the mass of the thermoplastic resin accounts for 50% or more of the total mass of the base sheet of the microprotrusion, and it is more preferable that the mass of the thermoplastic resin is 100%.
Examples of the thermoplastic resin include polyolefin, polyester, polyamide, polyamideimide, polyetheretherketone, polyetherimide, polyvinyl chloride, acrylic resin, polystyrene resin, and combinations thereof.
Examples of the polyolefin include polypropylene and polyethylene.
Examples of the polyester include polyethylene terephthalate, polyfatty acid ester, polylactic acid, polycaprolactane, polybutylene succinate, and the like.
Examples of polyamides include nylon and the like.
From the viewpoint of biodegradability, polyfatty acid esters are preferably used. Specific examples of the polyfatty acid ester include polylactic acid, polyglycolic acid, and combinations thereof.

The mass ratio of the thermoplastic resin contained in the injection needles 1A, 1B to the total mass of the injection needles 1A, 1B, 1C is preferably 50% or more, from the viewpoint of improving the moldability and dimensional stability of the injection needles. More preferably it is 70% or more, still more preferably 90% or more.
Further, the mass ratio of the thermoplastic resin is preferably 100% or less, more preferably 98% or less, and even more preferably 96% or less, from the viewpoint of adding various effects to the injection needle, for example.
Further, the mass ratio of the thermoplastic resin is preferably 50% or more and 100% or less, more preferably 70% or more and 98% or less, and still more preferably 90% or more and 96% or less.
Here, as various functional agents, antibacterial agents, bactericidal agents, humectants, flow improvers, antistatic agents, colorants, etc. can be used.

Although the present invention has been described based on its preferred embodiments, the present invention is not limited to the above-described embodiments and can be modified as appropriate.
For example, in the first embodiment, the second protrusion 32 and the third protrusion 33 are solid, but the second protrusion 32 and the third protrusion 33 may be hollow. Further, in the second embodiment, the composite second protrusion 52 is solid, but the composite second protrusion 52 may be hollow. In the injection needles 1A, 1B, and 1C, the protrusions other than the first protrusion 31 are preferably solid. By doing so, it is possible to prevent the liquid to be discharged from the opening 31a of the first protrusion 31 from being stored inside other protrusions, so that the liquid can be injected efficiently.

Further, in the injection needles 1A to 1C, the protrusions are arranged in an array (single or multiple rows), but in addition to the array, the protrusions are arranged in circular, elliptical, square, rectangular, and hexagonal shapes. , an arbitrary arrangement such as an arrangement arranged in an arbitrary annular shape such as a star shape.
Further, in the injection needle 1A, the third protrusion 33 has a cylindrical shape, but the third protrusion 33 may have a truncated conical shape with a flat tip, or may have a conical shape with a curved tip surface. Further, the shape of the third protrusion 33 in plan view is not particularly limited, and may be circular, elliptical, square, rectangular, hexagonal, star-shaped, or the like.

Further, the injection needle of the present invention may have the first protrusion 31, the second protrusion 32, the composite first protrusion 51, and the composite second protrusion 52, or the first protrusion 31, the second protrusion 32, and the composite second protrusion 51. It may have the first protrusion 51, it may have the first protrusion 31, the second protrusion 32, and the composite second protrusion 52, or it may have the first protrusion 31 and the composite first protrusion 51. It may have a composite second protrusion 52, or it may have a composite first protrusion 51 and a composite second protrusion 52.

Further, the composite first protrusion 51 may be formed by integrally forming the puncture depth control section 40 around the plurality of first protrusions 31, as shown in FIG. 12(a). Further, the composite second protrusion 52 may be formed by integrally forming the puncture depth control section 40 around the plurality of second protrusions 32, as shown in FIG. 12(a).
Further, the second protrusion 32 may have a truncated circular shape in cross-sectional view, as shown in FIG. 12(b).
Moreover, the injection needle of the present invention may each have one first protrusion 31 and one second protrusion 32, or may have a plurality of them.

Regarding the embodiments of the present invention described above, the following additional notes are further disclosed.
<1>
It has a protrusion that protrudes from the seat base,
The protrusion includes a hollow first protrusion that has an opening at its tip, and a second protrusion that does not have an opening at its tip, and is lower than the tip of the first protrusion and located at the base of the sheet. A hypodermic needle having a puncture depth control in an intermediate position that is higher than the surface.

<2>
The injection needle according to <1>, wherein the puncture depth control section is located at a position lower than the tip position of the second protrusion.
<3>
The injection needle according to <1> or <2>, wherein the puncture depth control section controls the penetration depth of the first protrusion.
<4>
The injection needle according to any one of <1> to <3>, wherein the difference in height between the tip position of the first protrusion and the position of the puncture depth control section is 1 μm or more and 5000 μm or less.
<5>
The injection needle according to any one of <1> to <4>, wherein the difference in height between the tip position of the first protrusion and the position of the puncture depth control section is 5 μm or more.
<6>
The injection needle according to any one of <1> to <5>, wherein the difference in height between the tip position of the first protrusion and the position of the puncture depth control section is 4000 μm or less.

<7>
The injection needle according to any one of <1> to <6>, wherein the first protrusion is higher than the second protrusion.
<8>
The injection needle according to any one of <1> to <7>, comprising a composite first protrusion in which the puncture depth control section is integrally formed around the first protrusion.
<9>
The injection needle according to any one of <1> to <8>, comprising a composite second projection in which the puncture depth control section is integrally formed around the second projection.
<10>
The protrusion protruding from the sheet base includes a third protrusion arranged around the first protrusion or the second protrusion, and the third protrusion has a distal end surface serving as the puncture depth control part. , the injection needle according to any one of <1> to <9> above.

<11>
The injection needle according to any one of <1> to <10>, wherein the distance between the tips of the adjacent protrusions is 0.01 mm or more and 10 mm or less in a plan view of the sheet base.
<12>
The injection according to any one of <1> to <11>, wherein the distance between the tips of the adjacent protrusions is 0.1 mm or more, preferably more than 0.5 mm, in a plan view of the sheet base. needle.
<13>
The injection needle according to any one of <1> to <12>, wherein the distance between the tips of the adjacent protrusions is 5 mm or less, preferably less than 3 mm, in a plan view of the sheet base.

<14>
The injection needle according to any one of <1> to <13> above, wherein the protrusions other than the first protrusion are solid.
<15>
The injection needle according to any one of <1> to <14>, wherein the injection needle contains a thermoplastic resin.
<16>
The injection needle according to any one of <1> to <15> above, wherein the proportion of the mass of the thermoplastic resin contained in the injection needle to the total mass of the injection needle is 50% or more and 100 or less.
<17>
The injection needle according to any one of <1> to <16>, wherein the opening is not formed at the tip of the first protrusion, but is formed on the side surface of the first protrusion.

<18>
The injection according to any one of <1> to <17> above, wherein the difference H1-H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is 1 μm or more and 5000 μm or less. needle. <19>
The injection needle according to any one of <1> to <18>, wherein the difference H1-H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is 5 μm or more.
<20>
The injection needle according to any one of <1> to <19>, wherein the difference H1-H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is 4000 μm or less.

<21>
The injection needle according to any one of <1> to <20>, wherein the first protrusion has a tip diameter of 1 μm or more and 300 μm or less.
<22>
The injection needle according to any one of <1> to <21>, wherein the first protrusion has a tip diameter of 5 μm or more.
<23>
The injection needle according to any one of <1> to <22>, wherein the first protrusion has a tip diameter of 50 μm or less.
<24>
The injection needle according to any one of <1> to <23>, wherein the diameter of the tip of the second protrusion is greater than or equal to the diameter of the tip of the first protrusion.

<25>
The injection needle according to any one of <1> to <24>, wherein the first protrusion 31 has a protrusion height of 10 μm or more and 5000 μm or less.
<26>
The injection needle according to any one of <1> to <25>, wherein the first protrusion 31 has a protrusion height of 20 μm or more.
<27>
The injection needle according to any one of <1> to <26>, wherein the first protrusion 31 has a protrusion height of 4000 μm or less.

<28>
The injection needle according to any one of <1> to <27>, wherein the distance from the surface of the sheet base to the puncture depth control section is 5 μm or more and 4000 μm or less.
<29>
The injection needle according to any one of <1> to <28>, wherein the distance from the surface of the sheet base to the puncture depth control section is 10 μm or less.
<30>
The injection needle according to any one of <1> to <29>, wherein the distance from the surface of the sheet base to the puncture depth control section is 3000 μm or less.
<31>
The injection needle according to any one of <1> to <30>, each having a plurality of first protrusions and a plurality of second protrusions.
<32>
The injection needle according to any one of <1> to <31>, wherein the pair of second protrusions are arranged to sandwich the first protrusion.
<33>
The area according to any one of <1> to <32>, which has an area in which the total number of first protrusions and second protrusions per cm ² is 10 or more and 500 or less when viewed in plan. syringe needle.
<34>
Any of the above <1> to <33>, which has an area in which the total number of first protrusions and second protrusions per 1 cm ² is 20 or more, preferably 30 or more when viewed in plan. The injection needle according to (1) above.
<35>
Any of the above <1> to <34>, which has an area in which the total number of first protrusions and second protrusions per 1 cm ² is 300 or less, preferably 200 or less when viewed in plan. The injection needle according to (1) above.
<36>
The ratio N2/N1 of the number N2 of the ^second protrusions to the number N1 of the first protrusions 31 per cm 2 is 0.01 or more and 100 or less, according to any one of the above <1> to the above <35>. Needle.
<37>
Any one of the ^above <1> to <36>, wherein the ratio N2/N1 of the number N2 of the second protrusions to the number N1 of the first protrusions 31 per 1 cm 2 is 1 or more, preferably 2.4 or more. The syringe needle described in .
<38>
The ratio N2/N1 of the number N2 of the ^second protrusions to the number N1 of the first protrusions 31 per 1 cm 2 is 50 or less, preferably 10 or less, according to any one of the above <1> to the above <37>. injection needle.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples.

[Example 1]
An injection needle having the same configuration as the injection needle 1A shown in FIG. 1 and the same arrangement as in FIG. 5(a) was manufactured. The dimensions of each projection of the injection needle, the dimensions of the sheet base, the number of first projections per 1 cm ² , and the distance between the tips of adjacent first projections or second projections are as shown in Table 1. The injection needle was formed by subjecting a base sheet made of 100% polylactic acid, which is a thermoplastic resin, to protrusion formation using a processed needle to which ultrasonic vibrations were applied.
[Example 2]
An injection needle having the same configuration as the injection needle 1A shown in FIG. 1 and the same arrangement as in FIG. 5(d) was manufactured. It is the same as Example 1 except that each element is as shown in Table 1.
[Example 3]
An injection needle having the same configuration as the injection needle 1C shown in FIG. 9 and the same arrangement as in FIG. 11(a) was manufactured. It is the same as Example 1 except that each element is as shown in Table 1.
[Example 4]
An injection needle having the same configuration as the injection needle 1B shown in FIG. 6 and the same arrangement as in FIG. 8(a) was manufactured. It is the same as Example 1 except that each element is as shown in Table 1.
[Example 5]
An injection needle having the same configuration as the injection needle 1A shown in FIG. 1 and the same arrangement as in FIG. 5(f) was manufactured. It is the same as Example 1 except that each element is as shown in Table 1.
[Example 6]
An injection needle having the same configuration as the injection needle 1A shown in FIG. 1 and the same arrangement as in FIG. 14(a) was manufactured. It is the same as Example 1 except that each element is as shown in Table 1.
[Example 7]
An injection needle having the same configuration as the injection needle 1A shown in FIG. 1 and the same arrangement as in FIG. 14(b) was manufactured. It is the same as Example 1 except that each element is as shown in Table 1.
[Comparative example 1]
An injection needle having a first protrusion 31 and a third protrusion 33 was manufactured (see FIGS. 13(a) and (b)). It is the same as Example 1 except that each element is as shown in Table 1 and the protrusions 31 and 33 are arranged as shown in FIG. 13(b).

[Evaluation of flare reaction]
The flare reaction of the injection needles of Examples 1 to 7 and Comparative Example 1 was evaluated by the following method.
The injection needles of Examples 1 to 7 and Comparative Example 1 were each applied to the skin of the test subject and pressed for 10 seconds with a load of about 5N. After pressing for 10 seconds, the microprotrusion tool was peeled off, and the area where the microprotrusion tool was pressed was observed with a microscope at a magnification of 30 times, and the range of flare reaction was evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: Area exclusive to flare reaction is 70% or more B: Area exclusive to flare reaction is 30% or more and less than 70% C: Area exclusive to flare reaction is 10% or more and less than 30% D: Area exclusive to flare reaction is 0% or more Less than 10% The flare reaction exclusive area was calculated using the following formula.
Flare reaction exclusive area (%) = area where flare reaction occurred/area of protrusion placement area x 100
The area of the protrusion arrangement region was defined as the area surrounded by the outermost protrusions 31, 32, and 33 included in the region.

[Evaluation of drug injectability]
The drug injection properties of the injection needles of Examples 1 to 7 and Comparative Example 1 were evaluated by the following method.
The injection needles of Examples 1 to 7 and Comparative Example 1 were each attached to a syringe (manufactured by Hamilton Company, GASTIGHT #1710), and tilted 10 degrees from the vertical with a load of 2N or more while recoiling against the extracted pigskin. Puncture was performed, and 100 μL of the drug solution was injected at an injection rate of 1 μL/sec. After injection, the syringe was removed from the pig skin, and any overflowing or leaking drug that did not enter the pig skin was wiped away with a rag. Measure the weight of the excised pig skin before and after injection of the drug solution, take the difference in weight from the pig skin before injection of the drug solution as the injection amount of the drug solution, and evaluate using the following criteria with injection amount / dosage x 100 as the injection ratio (%) I did it. Regarding the puncture depth of the injection needle, it was confirmed that the puncture of the first protrusion was suppressed by the puncture depth control unit.
The evaluation results are shown in Table 1.
A: Injection ratio 75% or more and 100% or less B: Injection ratio 50% or more and less than 75% C: Injection ratio 25% or more and less than 50% D: Injection ratio 0% or more and less than 25%

As shown in Table 1, the injection needle of Comparative Example 1 was evaluated as B for flare reaction, but was evaluated as D for drug injectability. In other words, it can be seen that while the injection needle of Comparative Example 1 can achieve the effect of promoting blood flow, it is difficult to inject liquid. In addition, when evaluating the injectability of the drug, the injection needle of Comparative Example 1 may not be easy to insert. The drug leaked and was difficult to inject.
In contrast to the injection needle of Comparative Example 1, the injection needles of Examples 1 to 7 were evaluated as A, B, or C for flare reaction, and evaluated as A or B for drug injectability. In other words, it can be seen that the injection needles of Examples 1 to 7 can not only easily inject liquid, but also have the effect of promoting blood flow.

1A to 1C injection needle 20 sheet base 31 first protrusion 32 second protrusion 33 third protrusion 40 puncture depth control section

Claims (11)

An injection needle having a protrusion protruding from the base of the sheet,
The protrusion includes a hollow first protrusion that has an opening at its tip, and a second protrusion that does not have an opening at its tip,
The first protrusion and the second protrusion are fine protrusions whose protrusion height from the surface of the sheet base is 5000 μm or less ,
In the protrusion direction of the protrusion, when looking at the side closer to the surface of the sheet base as the lower side and the side farther from the surface of the sheet base as the higher side,
having a puncture depth control section at an intermediate position that is lower than the tip position of the first protrusion and higher than the surface of the sheet base;
In the injection needle, the puncture depth control section is located at a position lower than the tip position of the second protrusion. An injection needle having a protrusion protruding from the base of the sheet,
The protrusion includes a hollow first protrusion that has an opening at its tip, and a second protrusion that does not have an opening at its tip,
The first protrusion and the second protrusion are fine protrusions whose protrusion height from the surface of the sheet base is 5000 μm or less ,
In the protrusion direction of the protrusion, when looking at the side closer to the surface of the sheet base as the lower side and the side farther from the surface of the sheet base as the higher side,
having a puncture depth control section at an intermediate position that is lower than the tip position of the first protrusion and higher than the surface of the sheet base;
The protrusion protruding from the sheet base includes a third protrusion disposed around the first protrusion or the second protrusion, and the third protrusion has a distal end surface that is connected to the puncture depth control section. has become ,
In the injection needle, the puncture depth control section is located at a lower position than the tip position of the second protrusion, or at a position at the same height as the tip position of the second protrusion. An injection needle having a protrusion protruding from the base of the sheet,
The protrusion includes a hollow first protrusion that has an opening at its tip, and a second protrusion that does not have an opening at its tip,
The first protrusion and the second protrusion are fine protrusions whose protrusion height from the surface of the sheet base is 5000 μm or less ,
In the protrusion direction of the protrusion, when looking at the side closer to the surface of the sheet base as the lower side and the side farther from the surface of the sheet base as the higher side,
having a puncture depth control section at an intermediate position that is lower than the tip position of the first protrusion and higher than the surface of the sheet base;
comprising a composite second protrusion in which the puncture depth control section is integrally formed around the second protrusion ;
In the injection needle, the puncture depth control section is located at a lower position than the tip position of the second protrusion, or at a position at the same height as the tip position of the second protrusion. The injection needle according to any one of claims 1 to 3, wherein the difference in height between the tip position of the first protrusion and the position of the puncture depth control section is 1 μm or more and 5000 μm or less. The injection needle according to any one of claims 1 to 3, wherein the first protrusion is taller than the second protrusion. The injection needle according to any one of claims 1 to 3, wherein the distance between the tips of the adjacent protrusions is 0.01 mm or more and 10 mm or less in a plan view of the sheet base. The area according to any one of claims 1 to 3, having an area in which the total number of the first protrusions and the second protrusions per cm ² is 10 or more and 500 or less when viewed in plan. Needle. The injection needle according to any one of claims 1 to 3, ^wherein the ratio N2/N1 of the number N2 of the second protrusions to the number N1 of the first protrusions per cm 2 is 0.01 or more and 100 or less. . A plurality of second protrusions are arranged to surround the first protrusions, a plurality of third protrusions are arranged to surround the plurality of second protrusions, and a plurality of third protrusions are arranged to surround the plurality of second protrusions. The injection needle according to claim 1 or 3, wherein a distal end surface of the protrusion serves as the puncture depth control section. The injection needle according to any one of claims 1 to 3, wherein a liquid drug is stored in the hollow part of the first protrusion. An injection device comprising the injection needle according to any one of claims 1 to 3 and a drug supply device capable of supplying a drug to the first protrusion of the injection needle.

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